Republican presidential candidate and former Pennsylvania Senator Rick Santorum arrives at a campaign stop in Manchester, New Hampshire, January 6. The New Hampshire Republican presidential primary election is on January 10.

In the latest WMUR New Hampshire Primary Poll, conducted by the University of New Hampshire Survey Center, Mr. Romney leads with 41 percent, down from 46 percent on Jan. 2-3. Texas Representative Paul polls at 17 percent, down from 23 percent. Mr. Santorum, the near winner of last week’s Iowa caucuses, is tied with Mr. Huntsman at 11 percent, both up from early January. And Mr. Gingrich is holding steady at 8 percent.

Romney, the former governor of neighboring Massachusetts, is battling only the expectation that he will win big in the Granite State – and is likely to head into South Carolina and Florida (Jan. 31) with momentum. Romney has surged into the lead in South Carolina and Florida polls. So the question out of New Hampshire is, Who besides Romney lives to fight another day?

Andy Smith, director of the UNH Survey Center, offers a caveat: Beware the late deciders.

“New Hampshire voters historically have made up their minds in the final days before the election and campaign activities in the final days matter,” Mr. Smith writes in his poll analysis.

The UNH poll shows only 44 percent of likely New Hampshire voters have made a definite choice, while 27 percent are leaning toward a candidate and 29 percent are undecided. When pushed to make a choice, undecided voters went for Romney with 43 percent, followed by Paul (18 percent), Huntsman (14), Santorum (12), and Gingrich (9).

Huntsman skipped last week’s Iowa caucuses and has staked his campaign on New Hampshire. If he fails to finish strong here, it’s not clear that he will have the funds to continue into South Carolina.

Working in Huntsman’s favor in New Hampshire is that independent voters – who account for more than one-third of the state’s electorate – are allowed to vote in the primary. Huntsman, who served as President Obama’s ambassador to China until last year, has shaped an image as a centrist, willing to work across the aisle.

In Sunday morning’s debate on NBC’s “Meet the Press,” Huntsman went after Romney over a comment he had made the night before, in a debate on ABC.

"I was criticized last night by Governor Romney for putting my country first," Huntsman said. "He criticized me, while he was out raising money, for serving my country in China. Yes, under a Democrat. Like my two sons are doing in the United States Navy. They're not asking what political affiliation the president is. I want to be very clear with the people here in New Hampshire and this country: I will always put my country first.”

Santorum also has something to prove in New Hampshire – that he can keep at least some measure of his Iowa momentum alive. But he is also looking ahead to South Carolina, where his religious conservative profile is probably a better fit than in New Hampshire. He campaigned there on Sunday, before returning to a full day of campaigning Monday in the Granite State. But without a reasonably strong finish here, it’s not clear that the former Pennsylvania senator will have the resources to continue much beyond South Carolina.